In his factory in Bogota, Miguel Caballero makes bullet-proof vests attached to bullet-proof backpacks which he has tested with machine guns and handguns to show they can withstand a barrage of bullets.

Mr Caballero said that following the December 14 mass shooting at Sandy Hook Elementary in Newtown, his company received a surge in customer interest in this kind of item.

"We started getting e-mails from customers asking for protective clothing because they were afraid to take their kids to school," said Mr Caballero on the factory floor where his company's clothing is made.